The objective of the project is to describe the functions of fibronectin and related glycoproteins in normal and pathological states. The project includes immunochemical and structural studies of purified fIbronectin, studies of fibronectin in cell culture, and observations of fibronectin in normal and diseased fluids and tissues. Results to date strongly suggest roles for fibronectin as a mediator for collagen fibrillogenesis during wound healing and embryonic development and as an adhesive molecule between cells and connective tissue matrices in mature tissues. In addition, plasma fibronectin can function as an opsonin for phagocytosis of gram-positive bacteria by neutrophils. Discrete portions of the fibronectin molecule are responsible for noncovalent binding of fibronectin to collagen, covalent binding (via gamma-glutamyl lysine cross-links) to collagen, and noncovalent binding to gram-positive bacteria.